This book appears in the Legerdemain Lounge, Dalaran (46.9,39.1). Go to the second floor, in the room to the left(west), on the usually empty bookshelf. Alternate book-spawns appear to be The Archmage Antonidas - Part III and To Do Today. The timer for respawns is between 3 and 4 hours. So if you see a comment in Trade chat, or the specific channels such as higherlearning (type /join higherlearning to see it), aim to return in three hours and calculate the respawn period for the book from there.